This invention relates to the assembly of seamed articles made from limp material, such as fabric. In particular, the invention relates to an apparatus for supporting fabric gripping elements along a deformable axis corresponding to a predetermined contour on a limp fabric segment.
Conventional assembly line manufacture of seamed articles constructed of limp fabric consists of a series of manually controlled assembly operations. Generally tactile presentation and control of the fabric-to-be-joined is made to the joining, or sewing, head under manual control. One drawback of this application technique is that the technique is labor intensive; that is, a large portion of the cost for manufacture is spent on labor. To reduce cost, automated or computer-controlled manufacturing techniques have been proposed in the prior art.
The incorporated reference discloses a limp material handling system including a manipulating system for selectively manipulating one or more layers of limp material. The manipulating system includes a support assembly adapted to support the material on a reference surface. The manipulating system further includes a selectively operable fold assembly. The fold assembly is operative to grip a curvilinear region of the material, then to control the curvature of that gripped curvilinear region so that the region has a selected contour, and to selectively translate and rotate that gripped region to a selected location overlying an associated curvilinear region of the reference surface, and then the material is released. To fold the material, a lifting operation for the gripped region is interspersed with these operations. Then, that translated and/or rotated and/or configured curvilinear region is lowered to the underlying associated curvilinear region of the reference surface, or onto material overlying that associated curvilinear region on the reference surface.
More particularly, in accordance with the disclosure of incorporated reference, the material manipulation system for fabric on a support table, includes a controller, and the folding assembly. The folding assembly includes a controllable robot arm portion which is selectively movable along a reference axis perpendicular to the support table and selectively rotatable about that axis. The folding assembly includes an articulated assembly supporting a flexible spline extending along a deformable central axis parallel to the plane of the support table. That spline-supporting assembly includes three connected segments coupled in serial fashion. Each of the end segments is selectively rotatable with respect to the central segment, all under the control of the controller. The central segment is rotatable about the reference axis under the control of the controller. Each of segments includes a plurality of gripping elements distributed along the deformable central axis of the spline. In the incorporated reference, the spline is controlled generally to establish a desired orientation of gripping elements extending from the spline. Cubic or higher order spline curvatures may be achieved with this configuration.
It is an object of the present invention to provide an improved apparatus for controlling the shape of a flexible spline to substantially match a third order polynomial curve.